Mozilla Foundation Security Advisory 2009-01

Crashes with evidence of memory corruption (rv:1.9.0.6)

Announced

February 3, 2009

Reporter

Mozilla developers

Impact

Critical

Products

Firefox, SeaMonkey, Thunderbird

Fixed in

Firefox 3.0.6

SeaMonkey 1.1.15

Thunderbird 2.0.0.21

Mozilla developers identified and fixed several stability bugs in
the browser engine used in Firefox and other Mozilla-based
products. Some of these crashes showed evidence of memory corruption
under certain circumstances and we presume that with enough effort at
least some of these could be exploited to run arbitrary code.

Thunderbird shares the browser engine with Firefox and
could be vulnerable if JavaScript were to be enabled in mail. This is
not the default setting and we strongly discourage users from running
JavaScript in mail. Without further investigation we cannot rule out
the possibility that for some of these an attacker might be able to
prepare memory for exploitation through some means other than
JavaScript such as large images.

Workaround

Disable JavaScript until a version containing these fixes can be installed.